1. Field of the Invention
The present invention relates to a tent part, and more particularly to a top support structure of a tent frame.
2. Description of the Prior Art
A conventional automatic extendable tent frame comprises a top pivot holder. The pivot holder has pivot troughs for connection of support poles and elastic units which correspond in number to the support poles. When the support poles are folded downward with respect to the pivot holder, the elastic units provide elasticity. Each support pole is movably connected to the pivot holder and rotatable with relative to the pivot holder. One end of each elastic unit is connected to the support pole and another end of each elastic unit is connected to the pivot holder. It is required to apply a force to retract the support poles inward when folding the tent. When unfolding the tent, the restoring force of the elastic units will expand the support poles up relative to the pivot holder, providing an automatic extendable function. This shows that the top support frame of this tent depends on the elasticity of the elastic units. If the top of the tent is applied with a force, the support poles are easy to be folded downward. Thus, the support strength of the support poles is not enough. The outer support poles may be raised relative to the pivot holder subject to the elastic action of the elastic units. When the tent is influenced by wind force or external force, the tent frame is easy to shake. The tent lacks support stability.